The present invention relates to an optical recording and playback system using laser light beam to record or erase data on an optical magnetic recording media, and using a contact image sensor to reproduce the data recorded on the recording media. Optical recording and playback devices, which modulate predetermined data into laser light beam, record the modulated light beam on recording media, and reproduce or erase the recorded data, have continued to evolve for long time. The optical recording and playback devices conventionally have an optical system with a plurality of lenses which are commonly formed of glass materials.
In order to record laser light data on recording media using lenses as stated above, the system must include a lens driver which is an automatic focus controller that allows the focus of laser beam to be automatically set in wide range of the recording media. Representative examples of this composition already in practical use are compact disc players and video disc players. However, since the system records data on a given size recording media, in the above method of recording laser light data on discs, it has a disadvantage of limiting amount of data to be recorded.
On the other hand, an optical recording and playback device, an optical system, which does not require focus adjusting and is capable of recording, reproducing and erasing laser light data on an optical magnetic tape has been introduced. An example of this, is described in Japanese patent application serial no. 61-194644 AN OPTICAL RECORDING AND PLAYBACK DEVICE, published on Aug. 29, 1986 by HITACHI company. The optical recording and playback device has a tape guide that is round-end processed so that a surface of the recording tape is in line with focal locus of laser beam to allow focus of a laser beam focus lens and the surface of optical magnetic tape which is a recording media, to be always positioned within focal locus of the laser beam during beam-scanning.
However, since the device using the tape guide to have the focus of incident light beamed from a lens, always set on the surface of the tape, has the tape guide in contact with the optical magnetic tape, it not only damages the surface of the tape but also can cause the data to be contaminated.
And also during playback, the above optical recording and playback device must use Acoust-Optic (A/O) deflector since it picks up data recorded on tape by optical operation.